@article{96d79d4d3b314874952a4bca0236f609,
title = "K2-141 b: A 5- M ⊗ super-Earth transiting a K7 v star every 6.7 h",
abstract = "We report on the discovery of K2-141 b (EPIC 246393474 b), an ultra-short-period super-Earth on a 6.7 h orbit transiting an active K7 V star based on data from K2 campaign 12. We confirmed the planet's existence and measured its mass with a series of follow-up observations: seeing-limited Muscat imaging, NESSI high-resolution speckle observations, and FIES and HARPS high-precision radial-velocity monitoring. K2-141 b has a mass of 5.31 ± 0.46 M⊗ and radius of 1.54-0.09+0.10 R⊗, yielding a mean density of 8.00-1.45+1.83 g cm-3 and suggesting a rocky-iron composition. Models indicate that iron cannot exceed ∼70% of the total mass. With an orbital period of only 6.7 h, K2-141 b is the shortest-period planet known to date with a precisely determined mass.",
keywords = "Planetary systems, Planets and satellites: individual: EPIC 246393474 b, Stars: fundamental parameters, Stars: individual: EPIC 246393474, Techniques: photometric, Techniques: radial velocities",
author = "O. Barrag{\'a}n and D. Gandolfi and F. Dai and J. Livingston and Persson, {C. M.} and T. Hirano and N. Narita and Sz Csizmadia and Winn, {J. N.} and D. Nespral and J. Prieto-Arranz and Smith, {A. M.S.} and G. Nowak and S. Albrecht and G. Antoniciello and {Bo Justesen}, A. and J. Cabrera and Cochran, {W. D.} and H. Deeg and Ph Eigmuller and M. Endl and A. Erikson and M. Fridlund and A. Fukui and S. Grziwa and E. Guenther and Hatzes, {A. P.} and D. Hidalgo and Johnson, {M. C.} and J. Korth and E. Palle and M. Patzold and H. Rauer and Y. Tanaka and {Van Eylen}, V.",
note = "Funding Information: Acknowledgements. We are very grateful to the NOT and ESO staff members for their unique and superb support during the observations. Data presented herein were obtained at the WIYN Observatory from telescope time allocated to NN-EXPLORE through the scientific partnership of the National Aeronautics and Space Administration, the National Science Foundation, and the National Optical Astronomy Observatory, obtained as part of an approved NOAO observing program (P. I. Livingston, proposal ID 2017B-0334). NESSI was built at the Ames Research Center by Steve B. Howell, Nic Scott, Elliott P. Horch, and Emmett Quigley. D. G. gratefully acknowledges the financial support of the Programma Giovani Ricercatori – Rita Levi Montalcini – Rientro dei Cervelli (2012) awarded by the Italian Ministry of Education, Universities and Research (MIUR). This work is partly financed by the Spanish Ministry of Economics and Competitiveness through projects ESP2014-57495-C2-1-R and ESP2016-80435-C2-2-R. M. F. and C. M. P. acknowledge generous support from the Swedish National Space Board. Sz. Cs. thanks the Hungarian OTKA Grant K113117. This paper includes data collected by the Kepler mission. Funding for the Kepler mission is provided by the NASA Science Mission directorate. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC; https://www. Funding Information: cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This publication makes use of VOSA, developed under the Spanish Virtual Observatory project supported from the Spanish MICINN through grant AyA2011-24052. Publisher Copyright: {\textcopyright} ESO 2018.",
year = "2018",
month = apr,
day = "1",
doi = "10.1051/0004-6361/201732217",
language = "English (US)",
volume = "612",
journal = "Astronomy and Astrophysics",
issn = "0004-6361",
publisher = "EDP Sciences",
}